<!DOCTYPE html>
<html lang="zh-CN" data-theme="light">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width,initial-scale=1" />
    <meta name="generator" content="VuePress 2.0.0-beta.61" />
    <meta name="theme" content="VuePress Theme Hope" />
    <link rel="alternate" hreflang="en-us" href="https://iotdb.apache.org/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html"><meta property="og:url" content="https://iotdb.apache.org/zh/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html"><meta property="og:site_name" content="IoTDB Website"><meta property="og:title" content="死区处理"><meta property="og:description" content="旋转门压缩 旋转门压缩（SDT）算法是一种死区处理算法。SDT 的计算复杂度较低，并使用线性趋势来表示大量数据。 在 IoTDB 中，SDT 在刷新到磁盘时会压缩并丢弃数据。 IoTDB 允许您在创建时间序列时指定 SDT 的属性，并支持以下三个属性： CompDev （Compression Deviation，压缩偏差）; CompDev 是 SD..."><meta property="og:type" content="article"><meta property="og:locale" content="zh-CN"><meta property="og:locale:alternate" content="en-US"><script type="application/ld+json">{"@context":"https://schema.org","@type":"Article","headline":"死区处理","image":[""],"dateModified":null,"author":[]}</script><link rel="icon" href="/favicon.ico"><meta name="Description" content="Apache IoTDB: Time Series Database for IoT"><meta name="Keywords" content="TSDB, time series, time series database, IoTDB, IoT database, IoT data management,时序数据库, 时间序列管理, IoTDB, 物联网数据库, 实时数据库, 物联网数据管理, 物联网数据"><meta name="baidu-site-verification" content="wfKETzB3OT"><meta name="google-site-verification" content="mZWAoRY0yj_HAr-s47zHCGHzx5Ju-RVm5wDbPnwQYFo"><title>死区处理 | IoTDB Website</title><meta name="description" content="旋转门压缩 旋转门压缩（SDT）算法是一种死区处理算法。SDT 的计算复杂度较低，并使用线性趋势来表示大量数据。 在 IoTDB 中，SDT 在刷新到磁盘时会压缩并丢弃数据。 IoTDB 允许您在创建时间序列时指定 SDT 的属性，并支持以下三个属性： CompDev （Compression Deviation，压缩偏差）; CompDev 是 SD...">
    <style>
      :root {
        --bg-color: #fff;
      }

      html[data-theme="dark"] {
        --bg-color: #1d1e1f;
      }

      html,
      body {
        background: var(--bg-color);
      }
    </style>
    <script>
      const userMode = localStorage.getItem("vuepress-theme-hope-scheme");
      const systemDarkMode =
        window.matchMedia &&
        window.matchMedia("(prefers-color-scheme: dark)").matches;

      if (userMode === "dark" || (userMode !== "light" && systemDarkMode)) {
        document.documentElement.setAttribute("data-theme", "dark");
      }
    </script>
    <link rel="preload" href="/assets/style-2f652485.css" as="style"><link rel="stylesheet" href="/assets/style-2f652485.css">
    <link rel="modulepreload" href="/assets/app-cbe6e1e7.js"><link rel="modulepreload" href="/assets/framework-44b8a372.js"><link rel="modulepreload" href="/assets/Deadband-Process.html-0d23c4e4.js"><link rel="modulepreload" href="/assets/Deadband-Process.html-90094a2e.js">
  </head>
  <body>
    <div id="app"><!--[--><!--[--><!--[--><span tabindex="-1"></span><a href="#main-content" class="skip-link sr-only">跳至主要內容</a><!--]--><!--[--><div class="theme-container has-toc"><!--[--><header class="navbar hide-icon" id="navbar"><div class="navbar-start"><button class="toggle-sidebar-button" title="Toggle Sidebar"><span class="icon"></span></button><!--[--><!----><!--]--><a href="/zh/" class="brand"><img class="logo" src="/logo.png" alt="IoTDB Website"><!----><span class="site-name hide-in-pad">IoTDB Website</span></a><!--[--><!----><!--]--></div><div class="navbar-center"><!--[--><!----><!--]--><!--[--><!----><!--]--></div><div class="navbar-end"><!--[--><!----><!--]--><div id="docsearch-container"></div><nav class="nav-links"><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="文档"><span class="title"><!---->文档</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/zh/UserGuide/Master/QuickStart/QuickStart.html" class="nav-link" aria-label="latest"><!---->latest<!----></a></li><li class="dropdown-item"><a href="/zh/UserGuide/V1.2.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v1.2.x"><!---->v1.2.x<!----></a></li><li class="dropdown-item"><a href="/zh/UserGuide/V1.1.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v1.1.x"><!---->v1.1.x<!----></a></li><li class="dropdown-item"><a href="/zh/UserGuide/V1.0.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v1.0.x"><!---->v1.0.x<!----></a></li><li class="dropdown-item"><a href="/zh/UserGuide/V0.13.x/QuickStart/QuickStart.html" class="nav-link" aria-label="v0.13.x"><!---->v0.13.x<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><a href="https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=177051872" rel="noopener noreferrer" target="_blank" aria-label="系统设计" class="nav-link"><!---->系统设计<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="nav-item hide-in-mobile"><a href="/zh/Download/" class="nav-link" aria-label="下载"><!---->下载<!----></a></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="社区"><span class="title"><!---->社区</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/zh/Community/About.html" class="nav-link" aria-label="关于社区"><!---->关于社区<!----></a></li><li class="dropdown-item"><a href="https://cwiki.apache.org/confluence/display/iotdb" rel="noopener noreferrer" target="_blank" aria-label="Wiki" class="nav-link"><!---->Wiki<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="/zh/Community/Community-Project-Committers.html" class="nav-link" aria-label="开发人员"><!---->开发人员<!----></a></li><li class="dropdown-item"><a href="/zh/Community/Community-Powered-By.html" class="nav-link" aria-label="技术支持"><!---->技术支持<!----></a></li><li class="dropdown-item"><a href="/Community/Materials.html" class="nav-link" aria-label="活动与报告"><!---->活动与报告<!----></a></li><li class="dropdown-item"><a href="/zh/Community/Feedback.html" class="nav-link" aria-label="交流与反馈"><!---->交流与反馈<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="开发"><span class="title"><!---->开发</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/zh/Development/VoteRelease.html" class="nav-link" aria-label="如何投票"><!---->如何投票<!----></a></li><li class="dropdown-item"><a href="/zh/Development/HowToCommit.html" class="nav-link" aria-label="如何提交代码"><!---->如何提交代码<!----></a></li><li class="dropdown-item"><a href="/zh/Development/HowToJoin.html" class="nav-link" aria-label="成为Contributor"><!---->成为Contributor<!----></a></li><li class="dropdown-item"><a href="/zh/Development/Committer.html" class="nav-link" aria-label="成为Committer"><!---->成为Committer<!----></a></li><li class="dropdown-item"><a href="/zh/Development/ContributeGuide.html" class="nav-link" aria-label="项目开发指南"><!---->项目开发指南<!----></a></li><li class="dropdown-item"><a href="/zh/Development/HowtoContributeCode.html" class="nav-link" aria-label="技术贡献指南"><!---->技术贡献指南<!----></a></li><li class="dropdown-item"><a href="/zh/Development/format-changelist.html" class="nav-link" aria-label="TsFile的更改列表"><!---->TsFile的更改列表<!----></a></li><li class="dropdown-item"><a href="/zh/Development/rpc-changelist" class="nav-link" aria-label="RPC变更清单"><!---->RPC变更清单<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><div class="dropdown-wrapper"><button class="dropdown-title" type="button" aria-label="ASF"><span class="title"><!---->ASF</span><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="https://www.apache.org/" rel="noopener noreferrer" target="_blank" aria-label="基金会" class="nav-link"><!---->基金会<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/licenses/" rel="noopener noreferrer" target="_blank" aria-label="许可证" class="nav-link"><!---->许可证<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/security/" rel="noopener noreferrer" target="_blank" aria-label="安全" class="nav-link"><!---->安全<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/sponsorship.html" rel="noopener noreferrer" target="_blank" aria-label="赞助" class="nav-link"><!---->赞助<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/foundation/thanks.html" rel="noopener noreferrer" target="_blank" aria-label="致谢" class="nav-link"><!---->致谢<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li><li class="dropdown-item"><a href="https://www.apache.org/events/current-event" rel="noopener noreferrer" target="_blank" aria-label="活动" class="nav-link"><!---->活动<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></li></ul></button></div></div></nav><div class="nav-item"><div class="dropdown-wrapper i18n-dropdown"><button class="dropdown-title" type="button" aria-label="选择语言"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon i18n-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="i18n icon" style="width:1rem;height:1rem;vertical-align:middle;"><path d="M379.392 460.8 494.08 575.488l-42.496 102.4L307.2 532.48 138.24 701.44l-71.68-72.704L234.496 460.8l-45.056-45.056c-27.136-27.136-51.2-66.56-66.56-108.544h112.64c7.68 14.336 16.896 27.136 26.112 35.84l45.568 46.08 45.056-45.056C382.976 312.32 409.6 247.808 409.6 204.8H0V102.4h256V0h102.4v102.4h256v102.4H512c0 70.144-37.888 161.28-87.04 210.944L378.88 460.8zM576 870.4 512 1024H409.6l256-614.4H768l256 614.4H921.6l-64-153.6H576zM618.496 768h196.608L716.8 532.48 618.496 768z"></path></svg><!--]--><span class="arrow"></span><ul class="nav-dropdown"><li class="dropdown-item"><a href="/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html" class="nav-link" aria-label="English"><!---->English<!----></a></li><li class="dropdown-item"><a aria-current="page" href="/zh/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html" class="router-link-active router-link-exact-active nav-link active" aria-label="简体中文"><!---->简体中文<!----></a></li></ul></button></div></div><div class="nav-item hide-in-mobile"><button id="appearance-switch"><svg xmlns="http://www.w3.org/2000/svg" class="icon auto-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="auto icon" style="display:block;"><path d="M512 992C246.92 992 32 777.08 32 512S246.92 32 512 32s480 214.92 480 480-214.92 480-480 480zm0-840c-198.78 0-360 161.22-360 360 0 198.84 161.22 360 360 360s360-161.16 360-360c0-198.78-161.22-360-360-360zm0 660V212c165.72 0 300 134.34 300 300 0 165.72-134.28 300-300 300z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon dark-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="dark icon" style="display:none;"><path d="M524.8 938.667h-4.267a439.893 439.893 0 0 1-313.173-134.4 446.293 446.293 0 0 1-11.093-597.334A432.213 432.213 0 0 1 366.933 90.027a42.667 42.667 0 0 1 45.227 9.386 42.667 42.667 0 0 1 10.24 42.667 358.4 358.4 0 0 0 82.773 375.893 361.387 361.387 0 0 0 376.747 82.774 42.667 42.667 0 0 1 54.187 55.04 433.493 433.493 0 0 1-99.84 154.88 438.613 438.613 0 0 1-311.467 128z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" class="icon light-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="light icon" style="display:none;"><path d="M952 552h-80a40 40 0 0 1 0-80h80a40 40 0 0 1 0 80zM801.88 280.08a41 41 0 0 1-57.96-57.96l57.96-58a41.04 41.04 0 0 1 58 58l-58 57.96zM512 752a240 240 0 1 1 0-480 240 240 0 0 1 0 480zm0-560a40 40 0 0 1-40-40V72a40 40 0 0 1 80 0v80a40 40 0 0 1-40 40zm-289.88 88.08-58-57.96a41.04 41.04 0 0 1 58-58l57.96 58a41 41 0 0 1-57.96 57.96zM192 512a40 40 0 0 1-40 40H72a40 40 0 0 1 0-80h80a40 40 0 0 1 40 40zm30.12 231.92a41 41 0 0 1 57.96 57.96l-57.96 58a41.04 41.04 0 0 1-58-58l58-57.96zM512 832a40 40 0 0 1 40 40v80a40 40 0 0 1-80 0v-80a40 40 0 0 1 40-40zm289.88-88.08 58 57.96a41.04 41.04 0 0 1-58 58l-57.96-58a41 41 0 0 1 57.96-57.96z"></path></svg></button></div><div class="nav-item"><a class="repo-link" href="https://github.com/apache/iotdb" target="_blank" rel="noopener noreferrer" aria-label="GitHub"><svg xmlns="http://www.w3.org/2000/svg" class="icon github-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="github icon" style="width:1.25rem;height:1.25rem;vertical-align:middle;"><path d="M511.957 21.333C241.024 21.333 21.333 240.981 21.333 512c0 216.832 140.544 400.725 335.574 465.664 24.49 4.395 32.256-10.07 32.256-23.083 0-11.69.256-44.245 0-85.205-136.448 29.61-164.736-64.64-164.736-64.64-22.315-56.704-54.4-71.765-54.4-71.765-44.587-30.464 3.285-29.824 3.285-29.824 49.195 3.413 75.179 50.517 75.179 50.517 43.776 75.008 114.816 53.333 142.762 40.79 4.523-31.66 17.152-53.377 31.19-65.537-108.971-12.458-223.488-54.485-223.488-242.602 0-53.547 19.114-97.323 50.517-131.67-5.035-12.33-21.93-62.293 4.779-129.834 0 0 41.258-13.184 134.912 50.346a469.803 469.803 0 0 1 122.88-16.554c41.642.213 83.626 5.632 122.88 16.554 93.653-63.488 134.784-50.346 134.784-50.346 26.752 67.541 9.898 117.504 4.864 129.834 31.402 34.347 50.474 78.123 50.474 131.67 0 188.586-114.73 230.016-224.042 242.09 17.578 15.232 33.578 44.672 33.578 90.454v135.85c0 13.142 7.936 27.606 32.854 22.87C862.25 912.597 1002.667 728.747 1002.667 512c0-271.019-219.648-490.667-490.71-490.667z"></path></svg></a></div><!--[--><!----><!--]--><button class="toggle-navbar-button" aria-label="Toggle Navbar" aria-expanded="false" aria-controls="nav-screen"><span class="button-container"><span class="button-top"></span><span class="button-middle"></span><span class="button-bottom"></span></span></button></div></header><!----><!--]--><!----><div class="toggle-sidebar-wrapper"><span class="arrow start"></span></div><aside class="sidebar" id="sidebar"><!--[--><!----><!--]--><ul class="sidebar-links"><li><section class="sidebar-group"><p class="sidebar-heading"><!----><span class="title">IoTDB用户手册 (V1.0.x)</span><!----></p><ul class="sidebar-links"></ul></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">关于IoTDB</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">快速上手</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable active"><!----><span class="title">数据模式与概念</span><span class="arrow down"></span></button><ul class="sidebar-links"><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Data-Model-and-Terminology.html" class="nav-link sidebar-link sidebar-page" aria-label="数据模型"><!---->数据模型<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Schema-Template.html" class="nav-link sidebar-link sidebar-page" aria-label="元数据模板"><!---->元数据模板<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Data-Type.html" class="nav-link sidebar-link sidebar-page" aria-label="数据类型"><!---->数据类型<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a aria-current="page" href="/zh/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html" class="router-link-active router-link-exact-active nav-link active sidebar-link sidebar-page active" aria-label="死区处理"><!---->死区处理<!----></a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a aria-current="page" href="/zh/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html#旋转门压缩" class="router-link-active router-link-exact-active nav-link sidebar-link heading" aria-label="旋转门压缩"><!---->旋转门压缩<!----></a><ul class="sidebar-sub-headers"></ul></li></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Encoding.html" class="nav-link sidebar-link sidebar-page" aria-label="编码方式"><!---->编码方式<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Compression.html" class="nav-link sidebar-link sidebar-page" aria-label="压缩方式"><!---->压缩方式<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Time-Partition.html" class="nav-link sidebar-link sidebar-page" aria-label="数据的时间分区"><!---->数据的时间分区<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li><li><!--[--><a href="/zh/UserGuide/V1.0.x/Data-Concept/Time-zone.html" class="nav-link sidebar-link sidebar-page" aria-label="时区"><!---->时区<!----></a><ul class="sidebar-sub-headers"></ul><!--]--></li></ul></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">语法约定</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">应用编程接口</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">元数据操作</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">数据写入（数据更新）</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">数据删除</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">数据查询</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">运算符和函数</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">触发器</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">监控告警</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">权限管理</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">运维工具</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">端云协同</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">系统集成</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">分布式</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">FAQ</span><span class="arrow end"></span></button><!----></section></li><li><section class="sidebar-group"><button class="sidebar-heading clickable"><!----><span class="title">参考</span><span class="arrow end"></span></button><!----></section></li></ul><!--[--><!----><!--]--></aside><!--[--><main class="page" id="main-content"><!--[--><!----><nav class="breadcrumb disable"></nav><div class="page-title"><h1><!---->死区处理</h1><div class="page-info"><!----><!----><!----><!----><span class="page-reading-time-info" aria-label="阅读时间"><svg xmlns="http://www.w3.org/2000/svg" class="icon timer-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="timer icon"><path d="M799.387 122.15c4.402-2.978 7.38-7.897 7.38-13.463v-1.165c0-8.933-7.38-16.312-16.312-16.312H256.33c-8.933 0-16.311 7.38-16.311 16.312v1.165c0 5.825 2.977 10.874 7.637 13.592 4.143 194.44 97.22 354.963 220.201 392.763-122.204 37.542-214.893 196.511-220.2 389.397-4.661 5.049-7.638 11.651-7.638 19.03v5.825h566.49v-5.825c0-7.379-2.849-13.981-7.509-18.9-5.049-193.016-97.867-351.985-220.2-389.527 123.24-37.67 216.446-198.453 220.588-392.892zM531.16 450.445v352.632c117.674 1.553 211.787 40.778 211.787 88.676H304.097c0-48.286 95.149-87.382 213.728-88.676V450.445c-93.077-3.107-167.901-81.297-167.901-177.093 0-8.803 6.99-15.793 15.793-15.793 8.803 0 15.794 6.99 15.794 15.793 0 80.261 63.69 145.635 142.01 145.635s142.011-65.374 142.011-145.635c0-8.803 6.99-15.793 15.794-15.793s15.793 6.99 15.793 15.793c0 95.019-73.789 172.82-165.96 177.093z"></path></svg><span>大约 3 分钟</span><meta property="timeRequired" content="PT3M"></span><!----><!----></div><hr></div><div class="toc-place-holder"><aside id="toc"><!--[--><!----><!--]--><div class="toc-header">此页内容<button class="print-button" title="打印"><svg xmlns="http://www.w3.org/2000/svg" class="icon print-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="print icon"><path d="M819.2 364.8h-44.8V128c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v236.8h-44.8C145.067 364.8 96 413.867 96 473.6v192c0 59.733 49.067 108.8 108.8 108.8h44.8V896c0 17.067 14.933 32 32 32h460.8c17.067 0 32-14.933 32-32V774.4h44.8c59.733 0 108.8-49.067 108.8-108.8v-192c0-59.733-49.067-108.8-108.8-108.8zM313.6 160h396.8v204.8H313.6V160zm396.8 704H313.6V620.8h396.8V864zM864 665.6c0 25.6-19.2 44.8-44.8 44.8h-44.8V588.8c0-17.067-14.933-32-32-32H281.6c-17.067 0-32 14.933-32 32v121.6h-44.8c-25.6 0-44.8-19.2-44.8-44.8v-192c0-25.6 19.2-44.8 44.8-44.8h614.4c25.6 0 44.8 19.2 44.8 44.8v192z"></path></svg></button></div><div class="toc-wrapper"><ul class="toc-list"><!--[--><li class="toc-item"><a aria-current="page" href="/zh/UserGuide/V1.0.x/Data-Concept/Deadband-Process.html#旋转门压缩" class="router-link-active router-link-exact-active toc-link level2">旋转门压缩</a></li><!----><!--]--></ul></div><!--[--><!----><!--]--></aside></div><!----><div class="theme-hope-content"><!--

    Licensed to the Apache Software Foundation (ASF) under one
    or more contributor license agreements.  See the NOTICE file
    distributed with this work for additional information
    regarding copyright ownership.  The ASF licenses this file
    to you under the Apache License, Version 2.0 (the
    "License"); you may not use this file except in compliance
    with the License.  You may obtain a copy of the License at
    
        http://www.apache.org/licenses/LICENSE-2.0
    
    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.

--><h1 id="死区处理" tabindex="-1"><a class="header-anchor" href="#死区处理" aria-hidden="true">#</a> 死区处理</h1><h2 id="旋转门压缩" tabindex="-1"><a class="header-anchor" href="#旋转门压缩" aria-hidden="true">#</a> 旋转门压缩</h2><p>旋转门压缩（SDT）算法是一种死区处理算法。SDT 的计算复杂度较低，并使用线性趋势来表示大量数据。</p><p>在 IoTDB 中，SDT 在刷新到磁盘时会压缩并丢弃数据。</p><p>IoTDB 允许您在创建时间序列时指定 SDT 的属性，并支持以下三个属性：</p><ul><li>CompDev （Compression Deviation，压缩偏差）</li></ul><p>CompDev 是 SDT 中最重要的参数，它表示当前样本与当前线性趋势之间的最大差值。CompDev 设置的值需要大于 0。</p><ul><li>CompMinTime （Compression Minimum Time Interval，最小压缩时间间隔）</li></ul><p>CompMinTime 是测量两个存储的数据点之间的时间距离的参数，用于减少噪声。 如果当前点和最后存储的点之间的时间间隔小于或等于其值，则无论压缩偏差如何，都不会存储当前点。 默认值为 0，单位为毫秒。</p><ul><li>CompMaxTime （Compression Maximum Time Interval，最大压缩时间间隔）</li></ul><p>CompMaxTime 是测量两个存储的数据点之间的时间距离的参数。 如果当前点和最后一个存储点之间的时间间隔大于或等于其值， 无论压缩偏差如何，都将存储当前点。 默认值为 9,223,372,036,854,775,807，单位为毫秒。</p><p>支持的数据类型：</p><ul><li>INT32（整型）</li><li>INT64（长整型）</li><li>FLOAT（单精度浮点数）</li><li>DOUBLE（双精度浮点数）</li></ul><p>SDT 的指定语法详见本文 <a href="/zh/UserGuide/V1.0.x/Reference/SQL-Reference.html" class="">SQL 参考文档</a>。</p><p>以下是使用 SDT 压缩的示例。</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB&gt; CREATE TIMESERIES root.sg1.d0.s0 WITH DATATYPE=INT32,ENCODING=PLAIN,DEADBAND=SDT,COMPDEV=2
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div></div></div><p>刷入磁盘和 SDT 压缩之前，结果如下所示：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB&gt; SELECT s0 FROM root.sg1.d0
+-----------------------------+--------------+
|                         Time|root.sg1.d0.s0|
+-----------------------------+--------------+
|2017-11-01T00:06:00.001+08:00|             1|
|2017-11-01T00:06:00.002+08:00|             1|
|2017-11-01T00:06:00.003+08:00|             1|
|2017-11-01T00:06:00.004+08:00|             1|
|2017-11-01T00:06:00.005+08:00|             1|
|2017-11-01T00:06:00.006+08:00|             1|
|2017-11-01T00:06:00.007+08:00|             1|
|2017-11-01T00:06:00.015+08:00|            10|
|2017-11-01T00:06:00.016+08:00|            20|
|2017-11-01T00:06:00.017+08:00|             1|
|2017-11-01T00:06:00.018+08:00|            30|
+-----------------------------+--------------+
Total line number = 11
It costs 0.008s
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>刷入磁盘和 SDT 压缩之后，结果如下所示：</p><div class="language-text line-numbers-mode" data-ext="text"><pre class="language-text"><code>IoTDB&gt; FLUSH
IoTDB&gt; SELECT s0 FROM root.sg1.d0
+-----------------------------+--------------+
|                         Time|root.sg1.d0.s0|
+-----------------------------+--------------+
|2017-11-01T00:06:00.001+08:00|             1|
|2017-11-01T00:06:00.007+08:00|             1|
|2017-11-01T00:06:00.015+08:00|            10|
|2017-11-01T00:06:00.016+08:00|            20|
|2017-11-01T00:06:00.017+08:00|             1|
+-----------------------------+--------------+
Total line number = 5
It costs 0.044s
</code></pre><div class="line-numbers" aria-hidden="true"><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div><div class="line-number"></div></div></div><p>SDT 在刷新到磁盘时进行压缩。 SDT 算法始终存储第一个点，并且不存储最后一个点。</p><p>时间范围在 [2017-11-01T00:06:00.001, 2017-11-01T00:06:00.007] 的数据在压缩偏差内，因此被压缩和丢弃。 之所以存储时间为 2017-11-01T00:06:00.007 的数据点，是因为下一个数据点 2017-11-01T00:06:00.015 的值超过压缩偏差。 当一个数据点超过压缩偏差时，SDT 将存储上一个读取的数据点，并重新计算上下压缩边界。作为最后一个数据点，不存储时间 2017-11-01T00:06:00.018。</p></div><!----><footer class="page-meta"><div class="meta-item edit-link"><a href="https://github.com/apache/iotdb/edit/rel/1.0/docs/zh/UserGuide/Data-Concept/Deadband-Process.md" rel="noopener noreferrer" target="_blank" aria-label="发现错误？在 GitHub 上编辑此页" class="nav-link label"><!--[--><svg xmlns="http://www.w3.org/2000/svg" class="icon edit-icon" viewBox="0 0 1024 1024" fill="currentColor" aria-label="edit icon"><path d="M430.818 653.65a60.46 60.46 0 0 1-50.96-93.281l71.69-114.012 7.773-10.365L816.038 80.138A60.46 60.46 0 0 1 859.225 62a60.46 60.46 0 0 1 43.186 18.138l43.186 43.186a60.46 60.46 0 0 1 0 86.373L588.879 565.55l-8.637 8.637-117.466 68.234a60.46 60.46 0 0 1-31.958 11.229z"></path><path d="M728.802 962H252.891A190.883 190.883 0 0 1 62.008 771.98V296.934a190.883 190.883 0 0 1 190.883-192.61h267.754a60.46 60.46 0 0 1 0 120.92H252.891a69.962 69.962 0 0 0-69.098 69.099V771.98a69.962 69.962 0 0 0 69.098 69.098h475.911A69.962 69.962 0 0 0 797.9 771.98V503.363a60.46 60.46 0 1 1 120.922 0V771.98A190.883 190.883 0 0 1 728.802 962z"></path></svg><!--]-->发现错误？在 GitHub 上编辑此页<span><svg class="external-link-icon" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path><polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg><span class="external-link-icon-sr-only">open in new window</span></span><!----></a></div><div class="meta-item git-info"><!----><!----></div></footer><nav class="page-nav"><a href="/zh/UserGuide/V1.0.x/Data-Concept/Data-Type.html" class="nav-link prev" aria-label="数据类型"><div class="hint"><span class="arrow start"></span>上一页</div><div class="link"><!---->数据类型</div></a><a href="/zh/UserGuide/V1.0.x/Data-Concept/Encoding.html" class="nav-link next" aria-label="编码方式"><div class="hint">下一页<span class="arrow end"></span></div><div class="link">编码方式<!----></div></a></nav><!----><!----><!--]--></main><!--]--><footer style="padding-bottom:2rem;"><span id="doc-version" style="display:none;">rel/1.0</span><p style="text-align:center;color:#909399;font-size:12px;margin:0 30px;">Copyright © 2023 The Apache Software Foundation.<br> Apache and the Apache feather logo are trademarks of The Apache Software Foundation</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"><strong>Have a question?</strong> Connect with us on QQ, WeChat, or Slack. <a href="https://github.com/apache/iotdb/issues/1995">Join the community</a> now.</p><p style="text-align:center;margin-top:10px;color:#909399;font-size:12px;margin:0 30px;"> We use <a href="https://analytics.google.com">Google Analytics</a> to collect anonymous, aggregated usage information. </p></footer></div><!--]--><!--]--><!----><!--]--></div>
    <script type="module" src="/assets/app-cbe6e1e7.js" defer></script>
  </body>
</html>